1. Field of Invention
This invention relates generally to changeable displays of graphic data by means of a multiplicity of pivotable disks movable between three positions for day and night viewing conditions; and more particularly, the invention involves a system and method employing a geometric or rectangular matrix of display disks in vertical columns and horizontal rows, selectively turnable to an upright front reflective position, an upright front non-reflective position, and a horizontal 90.degree. position for transmitting back light.
2. Description of the Prior Art
It has been known heretofore to provide a disk display capable of assuming three disk positions. The matrix display system described in U.S. Pat. No. 4,380,879 which issued Apr. 26, 1983 to L. Seibert, is typical of the three-position disk display matrices heretofore known. Such prior systems have a particular significant deficiency in that there is no positive mechanical way of holding the disks in a horizontal, light passing position. The prior systems rely on magnetic attraction of two angularly spaced electromagnets, which arrangement is not wholly satisfactory to effect 90.degree. horizontal positioning of the disks. Other objections pertain to the complex and expensive construction of the matrices; and the inability to insure that no disk can inadvertently turn to an upright forward light reflective position, when it is desired to turn the disk to a horizontal back lighting position.